SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d8df4d8d0b8c2ee3f37cfd7793a2be8501d01de8d23eac8060347a39d5a98a7' 
  AND token = 'JEWEMu4k6vGZUzBvleMrKdZYMbXJuXP/4liUmnpYePc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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