SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aa69930b071802c6833cd3787455f60ba2538964733e45012596c552ad1cfff2' 
  AND token = 'zCQ0YxkLulp41vKfZ3J8QZtavWLZXBO5vmjX/xbRZpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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