SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5628528fdb43eefed75c327b10243c340d5d3449861a81de96d29b7f8bc5a08' 
  AND token = 'CGgjV0Nc8SYFcgTGUp7YQzj95tuCwV1wkSJA9oQDpZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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