SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c6e9b55e682bf78f6693154f86fd435f34f85407f920c5955ea544428b71f5ff' 
  AND token = 'h7o62tV2hoosgKwuOfWP+bztwZgE9JKCX4qcPTkFXD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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