SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7c136c4e9d0c1162aba27b0a2330f9126254e19b48818ee0a6a670cb50e803a4' 
  AND token = 'BRwtz/LXgA6RuEVDjUZEJIWP9NcOfxBAE9MbuPEZTVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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