SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2777710fa9df82f9fd35263a86be1d7a80056bc2af427bae56f4cfdab1216a56' 
  AND token = 'LN38S1oD+9UkdQCWRfnO2CJeCmF+Fij/MCqg/u2rFFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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