SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc66d0197040a7c246061c615a69793a4123896babe41538b6b7e9b0b6b74852' 
  AND token = 'WavMqNQv/gYsrJijv+l3uylKEUpUwi/FQKGlgBwKkFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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