SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b0b1687cafc5f6179bcba5e2d6e9f7acea96c90441ed8df93c87d6349042cf' 
  AND token = 'Ni5hdpnnuuGlwT9jFGvYMpP3+4zSBOcGCy5aR9J3vw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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