SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f73628b6c32b32ed1c235304b1dcc3280dcbb3607afbcdfdfe09b5a2de190e2' 
  AND token = 'xlvsjjYxcp08bQSqNfO0k2O5fy5yjPihGS5h42sc+VY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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