SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7d39d1d9a35f749f2b0340df404103dafeb3f8fc585a1eeab59e74bd9333f58b' 
  AND token = 'VUKxwg+yOxFBcPDm8DkASkUH6Fqdrg2XCIDgc+VNBz4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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