SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81438fb9242450032526e9d833dadaeae65473e8334dae805e5a92111e38626b' 
  AND token = 'LOfbROPgf6Eh+1wmO12Q0qRlMYSvqQooW7JJidG+kbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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