SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '378e4bae7fefc355f226c23523f80428b2ddea031f14d1764e589d23918b8db1' 
  AND token = 'OXdb4SYsD/Xqhq5woXRM0Ph8qOok0ln0E23rcGrT8qY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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