SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '586acc27646365eec0a104449f2da38bacd64a73e9382777451f567fb0d9f073' 
  AND token = 'EbGj02RYC/Qsvcbt/ZDPrWVQUNASZIsPl17li+UJevI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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