SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dc094fa78f96fee94a1a8a92f9312056e6947a728f43445baa296c1ec4f83de' 
  AND token = 'esCSbnmdg0jkdARQ/3vgYl+J/MDEK2wG8T9tuwjIsDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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