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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9404db0581b9927f943b5d5701e14a58cfe80f67a7d3ffe0c0a2f2a6ea5f7f5' 
  AND token = 'QGJjumgNv6YO19i0gOudIxsqM7BFmUF00QNfCgVfPb0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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