SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ad196257fa5c5d56b3f25e2f6afb97924f5c056386ce5ad6758ef7326e4c7d0' 
  AND token = 'Qvo2iaaJijXxh8z/YugpKhpbiqeq8Zhc5KuoJi+ZVZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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