SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b135c1668379d199568de665509fbf1134d9a7ab48037b9efa7aaca8c6200707' 
  AND token = 'yJWYtDncEMLpKeqes1Ts82d9lDiZOlYSzconkNN2Iwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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