SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92bd6b71d9d03b5a1d1543d8816490e91391bf2f3bb6221e47ffbd4bfbc51e16' 
  AND token = '4Uft43fVSVGRvVLUdo1Cn3T4oPOfi9mSQEsN2sY3JLo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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