SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37e985f3e69043d49dcc66bae2070158dd335990b2b888d1dfc68c5e177e998d' 
  AND token = 'siN/rrbRsB+r18mVeIucMnctDB3P2GZQlSBiCEGs0vw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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