SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd1f5b9b9a87642167a9309a62bbbaddc289edc39f29f8d56af15651f80879a78' 
  AND token = 'PjPjppzlkSKpXx6stCWFgSOS4Rm4EDi1/0Lix9zGHBA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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