SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f91a4e37d06f2c17b5fdbe8d0b04ca920e19544691d50e12e81f0d43de713571' 
  AND token = 'oVAB748crXEwvP+8Zo6+K/JGvFLq9iiJzNBAagLZzcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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