SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02f159f7bd5c3b0740ae58f559eb39498f8d05188e275239816602c2625a4398' 
  AND token = '/ODf27GzAOqHaEBIZ74b5dHAR5EJvfNv/jy3LLJmNxk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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