SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a2d4f6facf52eb806612a82c249dbab474953ce89fcdb041a5c2b09815df565' 
  AND token = 'NSo3wRZEuGC/0YNDIj0FOgwSYnn3hXahG0K2wU6ezfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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