SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54fa5d70449d3398950be415ed2babcf62a5ffcaf3130044901a770268555a27' 
  AND token = 'pZH8HeUa1UblEMVDSqd1/WPG7lSkXPqVsh474dnyvaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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