SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd0bb1f178fbce4e7dbd46d3dbd9b5e1d20a796b80c225398f1985e65722543c0' 
  AND token = 'T8KISgCWXsjAi/zaJ/g/pz4fYTnzkndsTGxyNCBVPRE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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