SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b995722fa5a99b0b879eb3587fd543fe101ed435c69879146748c31c2f9b2248' 
  AND token = '7d/kZMxf8YUPQGlKfSer5pAw1DdV6BiLJR938/KgWW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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