SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '57c74a6bdfe21243c79c0fd865c87062298a41ae4d2f6e1768f89dac556197bb' 
  AND token = 'bBKZzKNpYDKwFl9t5AJoslYFdPPfO++URcq1EXMMXgA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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