SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1d3a7cf2fda8d54a8848a98c10e562d4d2070989d7e461e2932ac96de19dd42' 
  AND token = 'KthEFl3J394mcSBvsLey4i4od9SZWmxxys/RD4OJ7AQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}