SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cd1f69b03ea332ddb90f9ac79d0ad41094d5216b7fc98d698a980c848b284a9' 
  AND token = 'lsbz82WBYJWXgMHIRb49sLAyxoV5dI2tcka714A/mMg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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