SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '631cf254ae89e4199f71dd0861c31feab35c5bd2603a793534f5305ad2be6272' 
  AND token = 'ppK+fvYCK3qV3uHIWSgvZs4RSpn5smShiye6gZJJU+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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