SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8126a574f2ecd64e31b0f68170e892ece4ff6a8f865551e8ec1e208b66af1962' 
  AND token = 'ol4pQ4B2XryYm+/rG4f0xb+TedUBhLi9fAim/Cpgj18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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