SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e32398c2340f2e14b6a0a2334f39f7302de8766f4c3a142d585e7a1d03f1c895' 
  AND token = 'X2/Adw9yanE34PCTFQ+UZIUBXpzGzgvxWQ/FDCFX1fM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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