SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c09f4e286aa232ccdaa20d5e52e5695072258eb34724cc295822d888561959e' 
  AND token = 'cE/IWD6HQRkKAAGTH+ji6ZpK1NCot0tt5oCpts2Rkew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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