SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a436426b6254db1da085152d0dc38fb80217eff7e27f1b2809dc35c919fbd6ee' 
  AND token = 'GDtry96naExFQZhwcXzTaENRMpp+80WwtpLH3yjsKag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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