SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb862489744adea7081a7ef59addffadea1e9432ecc8dfde46e127dc118c47b' 
  AND token = 'nKkCCoS/FdKF3Og/OO83Dus9TZeCunKHfKkywnrJqn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00092

JSON explain

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