SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'feda0f0383f2a4579261febdbcd9df0fe0292795243c1b1cf29fc53e59598f15' 
  AND token = 'qCmFEpPqLXfE21eEtOEcg/XfwcAs59uMsTsst7G8IKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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