SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f75bf51de2ce34edb825f90a800b059f30d8eb82d98b4f1267a5dee722e3454f' 
  AND token = 'm7dA23l9tpvJBAaWmcqcghCXzQNApdxk4cr5Ebkg8bY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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