SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95b55f28b972125a344392d32638c9e58466f0e2e407032c909e8fe7540eedb5' 
  AND token = 'qcCHBckOyIbpGnMdbIAomnQb8mb8rQxAVyTTv76jBGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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