SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1880d91d702c29642ca4880acaff3c926f54968df1ebdaee07d9986a553475f0' 
  AND token = 'cN5936E+mH9ytQ1i/yYcz8k95aSUXc08ENO54wgprpM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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