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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0e7c4c28cc44ee3eef44b8f5b239e22e5c423327cb39e0c388be0b7e41ae3cb' 
  AND token = '/XEpw0fQkRdQCgLjtZkWuIM2S/OZSsfXkxNF7gHN/CM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}