SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0ea6ae757c0b3912f4a1e30410e824b3345347122b7d5fac1e068895c7663f4' 
  AND token = 'PA+vl0u75qk2jO9qgKHER3KmYFjQTlbEwvX0LIzGS7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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