SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11b0072d6781382de6f03160b7ec06e956f6514ee40805d878caafaa3708d446' 
  AND token = 'misct9F+rzAfcpJ7Vixl35Fb0Ovj0/CCggnGKhhvLE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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