SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1830bcbe9742da1b3629c8c90d1c5e0a2829f4b47ea85b0b14f0fae1ab99b1b' 
  AND token = 'uWfw05EUahDQj7+FRhTwJpC5oOeSmtuh+YrkcIjyMJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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