SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8d95b62f7dc53c35b967efce4711a8b4a3a59bf40ded6702cc8d0e01827080a' 
  AND token = 'Ng+9QFb3z8mYbWjJtO4X8hIU4s5NqL1zN4Rv/nZa/x4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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