SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ff654c07c259dc518305a3572e0e4bf892411f1783a04c363768b26267b2889' 
  AND token = 'UD7/jW1Zs0yrWJJaB61K5W4dOBibj/gWbfbf4lUrY+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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