SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f1d6371a8b5a76f67dd025ae18029b0fcbb7136a5f9f8ca2091f759d075bdf8' 
  AND token = 'oe9jDySzRXeRyZVCtmPAMbsndt3ax9AuoyRwlKGrEDw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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