SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b2d4d20d6bcaae4ed769b93230e609f496f061fa5d4018a290dc6834f02063d' 
  AND token = 'vALryTujXbLKBfCVSq01sFefU0b6H4o3+WKgJeg15q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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