SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e89ab88e5e805a3abed56842bf4afd1a62374a067be0f0558458c92dd8350f88' 
  AND token = '0NUWMayvxj3Up/xl/w8eLCFFe8En5kv1EBEi4znDQwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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