SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cadaa9c62409d97f44e35ce9873b1b8658759446aa9de5ad9ff66d4236e777f5' 
  AND token = 'dIEVoJmHyUeUBnqW7Jgx7mbGCVy/9/nOvIc+v+L+tKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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