SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '508e5fb87fc32b9ee0aa1ab8e9cfb2100c964936b688b561301bff17205f0914' 
  AND token = 'B3aNe6+oFjZFnXJeRXprcrv2u8+1UZz+J7GMr2CU9PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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