SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d95946a76ea8c390e1bf037daadd1980016117bda1190e00133721a7b12a06f' 
  AND token = 'MnwsFuesC8zuB2uW36Hqm4250xLa9JQwqrWrxxM3X70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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