SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '579990d2c48e0d8c52fb37ed1ecb3a4d077eeeda45f1f8d2455f0c8c5142da62' 
  AND token = 'AmIRcgAydCy0JEjDWpaxAxqa7Dn1szlwhok6gh38e1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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