SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '957c9e0b195251318e432f52cb5cf55accf8b84fea6b0068c81ab23e9b79f510' 
  AND token = 'MlowmWYBsjU6PFZJdgBmh5YsigHjhUTuLATA/vnUQOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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