SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368d30818845b09288021f73c0e657b5e3783ad30cf83bb219dcdfab778063e3' 
  AND token = 'Bw234utUOC/KsohWREPq5bw1DaVFtjj7rblcQITdWng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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