SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79fadab59cf2081274e269c3d17d67481d7f0673ba54531150e0b7a7d46e6ce0' 
  AND token = 'PTS1ZBpJrr2Xh753ls2/L9SSt7upo0VMhQL+oxpdFl4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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