SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3643c96fadac7f5b33d52a6db4611eb7edb8265652d0eb191d262f41fcaee741' 
  AND token = 'R7w1Qeqn6QkKywx2B5iieyrYzBx9+KqEPiJmEfb8eWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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