SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2bb40cae14a04144fbb1ee85393bdf6028654df4abd0671249e51563feb04ff' 
  AND token = 'E0PyXPjoHHXH4+eaiEq8hV3RhKYRkUc6INGQR4ULVBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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