SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8359a704d2550daefcfec2a22c2574f7cd0cb7898d7fe803ec479df157b13fb8' 
  AND token = 'vqTixI9cZebhTcyb2efVBdXysrOEz1aSr1/Ttn8wfrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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