SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae3baacef09113a167fc96e5b41373e659d6ee043511d7809a6cb2a115c04256' 
  AND token = 'QCbelUuyzAZAk1Sj0Szs2mHp/vgTdUhVaLkg8ALjsrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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