SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '455ec53d46c7d4fed87f6b314c1fb0aa6139ccd0a18c9791a3b217b6e27f3e87' 
  AND token = 'PdpY1+QYS0o9/z178R+NjvLPPB1gnsLs+2JBA9ftiOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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