SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef80191cf6474d544d39deb96ce67ae3178a0d930f7c1ce0c1f00bd4966cb773' 
  AND token = 'ZH1uDwgZ+7RK75PbI/1ccCKg88nFztmJbjoh3jqMfY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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