SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a14d643760ef0ec8423a03bff638f9e44f03c71048a301dab8f3621d3d71040' 
  AND token = 'gJS0Y7m7jnf3fovjiTCGOo4PgFy/aT/dzLo1sI/rkbo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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