SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd04a28da6262042ca7cb094b91da394f861d4078306ae3759e7cedc2762f8a2c' 
  AND token = 'oDcEWgjdgOl1X2dYeZ26p4KNNZlz/8nYgNDApL/LdkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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