SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56fdfd8be68b5577cbd9542f48fc7fb8ad85ffead4a51a163f60e99bab974fcc' 
  AND token = 'u6vOchpj9mqxWW3VNIR8llQoN1TRQkdHoR+4zjHlL5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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