SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9249923e26a86ee86a0075f1d300015d2922eb18017f8f937e5219ebc3463d26' 
  AND token = 'zAlwYYuCXrs1E/PY4XOceBdy8QqspV5Wq9FBzqfSNEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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