SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a35e508e3bd0616f77237a0cb0f4a7d70f14d1a5e240e2895f0640996da0a11' 
  AND token = 'l4sV6HY+cTkKS8Km+CAta32Y9J7o+PZU1MMVPCmXPcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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