SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f577578441e84a74c77c33690dae83f24bed956a60f1d207bf67b39b06f505a5' 
  AND token = 'ml50pPTMDAzdovjZpxcYGJkaGpFYF0mUB0JVY20zBLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00080

JSON explain

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