SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64961cd99efdbb98f317c761bcdecd721064c6a494f54e057c825425cad65f26' 
  AND token = 'kPEzz93RmL1TK4mkLsmQk3L57Z0P2fhVEar3/mvmeKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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