SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2713c821cb62cf5a9b2000ff7495ecb0d3d0d4fb0d8a50b923345e5ef1b4f7a4' 
  AND token = 'mUu4G/y8qNnlsgsnw5/rB9XpOcHpEL0AZJVcZDx+d74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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