SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7df0bd421aa1ece8763614e031168dbd3c3b7ca8233e5dc0905c48df888a9637' 
  AND token = 'fxYtCiqyu1LDegKkrtZG7a4Mvffngd14az04Ozaa40M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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