SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893173d7c1578a9476b0f5b91071f9ff28a7bf3614161ee5bc2992cf0db954a2' 
  AND token = 'rrLJTCD+Wu5eMZU+vDAf+PWypg7e973/wqqAWLIBPMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}