SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ef0d7611c2036a8f7c0573ea2fcbeed0f43d557051cd5bc210d4c75c644b538' 
  AND token = 'Cp+lU6Ec3If5ZKHR0TzG3vktngzzQBPVIPEWhxxhDQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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